Regulating device for arc-lamp circuits.



No. 684,34l. Patented w. a, I90l.

} m. H. BAKEB. REGULATING DEVICE FOR ABC LAMP CIRCUITS.

(Application fllod my 11, 1900.) (No Model.) 2 Shoots-Sheet I.

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REGULATING DEVICE FOR ARC LAIP CIRCUITS.

(Appliution fllod Kay 11, 1900.)

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UNITED STATES PATENT OFFICE.

MALCOLM I'I. BAKER, OF NEW YORK, N. Y., ASSIGNOR TO THE MANHATTANGENERAL CONSTRUCTION COMPANY, OF SAME PLACE.

REGULATING DEVICE FOR ARC-LAMP CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 684,341, dated October8, 1901. Application filed May 11,1900. Se ial No. 16,260. lNo model.)

To aZZ whom it may concern:

Be it known that I, MALCOLM H. BAKER, a citizen of the United States,and a resident of New York, in the county of New York and State of NewYork,have invented certain new and useful Improvements in RegulatingDevices for Arc-Lamp Circuits, of which the following is aspecification.

My invention relates to improvements in 1 o regulators for circuitscontaining alternatingcurrent arc-lamps arranged in series. Heretoforethe regulation of this class of devices has been accomplished throughthe medium of very complicated and expensive apparatus.

[5 By means of my present invention all complication is avoided and theregulation of a cur rent in an alternating-current arc-lam p seriescircuit is made certain and elfective by the use of very simplemechanism having few parts and very little liable to get out of order.

Myinvention relates, broadly, to automatically varying the reactance ina circuit such as described to compensate for changes in the resistanceof the circuit due to the cutting in or out of lamps or to any othercause.

Otherwise expressed, my invention relates to automatically varying thevalue of a variable reactance in the circuit in accordance with changesof resistance in the said circuit 39 in such a manner as to maintain thecurrent practically constant.

In carrying out my invention I include in the circuit in series with thelamps a reactance device consisting of a coil of wire so placed as tohave a free relative movement with respect to a laminated core insidethe coil. It is well understood that the current passing through a coilhaving such a relation to a magnetic core is more or'less choked or 40impeded, according to the relative position which the coil and the coreoccupy, the choking or impeding effect increasing with the farther andfarther insertion of the core within the coil and decreasing with thegradual with- 4 5 drawal of the core from the coil. The relativemovements of the coil and the core may be brought about by variations ofthe magnetic pull due to variations of the current passing through thecoil. If now a force could be discovered which would automatically varythe choking effect produced in the coil in correspondence withvariations in the resistance of the circuit,which force should opposeand vary with the magnetic pull of the said coil, the value of thecurrent traversing the coil might be made practically independent of theresistance of the circuit, so that a constant current could bemaintained irrespective of the number of lamps in operation in thocircuit. I have discovered that such a force can be suppliedmechanically in several ways.

In the present instance I make use of a spring connected either directlyor indirectly to the moving part of my regulating reactance device andalso connected at its opposite end to a fixed orstationary part of myapparatus. The arrangement is such that as the pull of the magnetincreases, owing to the switching out of lamps in the main circuit, asthe moving partof the reactancedeviceisgraduallydrawn down by theincrease of the magnetic pull the effect of the spring shall becorrespondingly increased, the spring being so constructed in the firstinstance as to have a gradually-hr creasing resistance under theinfluence of retraction, according to a determinate law. It

is to be understood that the parts are so connected as to cause thespring to be retracted or extended while the coil and its core are approaching each other and to be relieved while the coil and the core arebeing relatively sep arated.

I have illustrated my invention in the ac companying drawings, in which-Figure 1 shows my apparatus connected up with a group of lamps, theposition of the parts being that which they occupy at minimum load andthe spring being connected directly to the moving part of the reactancedevice. Fig. 2 is a similar view showing the position of the parts whenthe circuit is fully loaded. Fig. 3 shows my reactance device connectedindirectly with the counterbalancing-spring, and Figs. 4 and 5 arediagrammatic views illustrating the method by which a spring iscalibrated, so as to serve the purposes of my invention.

In the drawings, 1 is a suitable source of alternating current, and 2and 3 are electric mains leading therefrom. The lamps are shown at 4,andthe regulating or reactance coil appears at 5. The coil 5 isrepresented as surrounding one leg of a laminated iron core 6, ofhorseshoe shape, and its top is connected, in the form illustrated inFigs. 1 and 2, to a spring 7, the other end of which is attached to anarm 8 on a standard or upright 9. The Whole is mounted on a suitablebase 10.

The action of the apparatus will be readily understood. \Vhen the partsare in the position illustrated in Fig. 2, the movable portion of thereactance device is in its most elevated position. This represents theposition of the parts at maximum load. Should one or more lamps now becut out of the circuit and the resistance of the main circuit be therebydecreased, the coil of the reactance device will exercise a strongerpull upon its core and these two parts will approach each other, at thesame time stretching or extending the spring 7. Meanwhile the pull ofthe magnet has been constantly increasing, and it will also be notedthat the eflfectiveness of the spring has also been increasing by reasonof the qualities inherent in its construction, as above described.Accordingly the effect of the spring increases in the same ratio as thepullof the coreincreases, and it the spring is originally constructed sothat its increase of resistance, on being stretched, shall correspond tothe increasing pull of the magnet under the conditions of actual servicea substantial counterbalance can be maintained throughout the entireexcursion of the reactance coil or core, as the case may be. Asintimated, the spring 7 may be attached to the core 6 instead of to thecoil 5. The action would be the same in either case.

The particular shape of the core of the reactance device may be varied.In the present instance I make use of a laminated horseshoe-core, withthe coil arranged around one leg thereof. Moreover, my apparatus maybe'applied to a single series of arc-lamps, as shown in the drawings, ora number of them may be combined with several series of lamps.

In Fig. 3 I show a regulating reactance de vice in which the coil 5 isconnected by a link 11 with a lever 12, centrally pivoted at the top ofa standard 13. To the opposite end of the said lever is joined a spring7, the farther end of which is attached through an eye 14 to the base10. In this instance the core of the reactance device is ofdouble-horseshoe shape, the coil .5 being mounted on the central leg ofthe core. Whether the counterbalancing-spring is connected directly tothe moving part of the reactance device, as shown in Fig. 1, orindirectly, as shown in Fig. 3, makes no difference with the operationof my device.

Figs. 4: and 5 illustrate a method which may be employed for calibratinga spring to serve the purposes of my invention. Referring to Fig. 4, themovable part 5 of my reactance device is here shown as being suspendedfrom a frame or standard 9 by means of a springbalance l5,connected withan adjusting-screw 16. It will be understood that the size of the coil 5is determined the same as any standard regulator-that is, a sufficientnumber of turns of wire are wound upon the coil to choke the desirednumber of volt-s when the coil is all the way down on the iron. The coilbeing in this position, as shown in Fig. 4, the screw 16 is adjusteduntil the coil is in equilibrium at the desired current, this being theposition of no load. The number of pounds pull is read from thespring-balance and the position is noted. Half the load of'lamps, forinstance, may now be turned on and the spring-balance raised by means ofthe screw 16 until a new position of equilibrium for the desiredcurrent-say seven amperes-is found, the pounds and the position beingagain noted. The same operation is repeated for a full load of lamps,and in this way three points, A, B, and O, are determined, thus giving acalibration-scale. Instead of choosing conditions of no load, half-load,and full load only a scale may be formed, depending on a much largerselection of circuit conditions,

' thus obtaining, if desired, a reading for every change of conditiondue to the switching in of a single new translating device. The scalehaving been obtained, as indicated, the problem now is to wind a springthat will meet the conditions of the scale. Let it be assumed that thenumber of pounds pull when the coil is in its lowermost position is onehundred and that the pull under conditions of half-load is eightypounds, and that the pull under conditions of full load is fifty-fivepounds. The first thing to do in order to secure a spring which willfulfil the conditions demanded of it is to select a spring of approximately the same length as the total travel on the calibration-scale. Thespring must also be of such size and strength that when nearly closed itwill support fifty-five pounds, if that be the number of poundsindicated by the spring-balance for the position 0. Let this spring besuspended from the standard 9 and capable of adjustment therein by meansof an adj usting-screw 16. The screw should then be adjusted so that thepointer 17 is opposite the line indicating the position 0, when a weightof fifty-five pounds is hung at the lower end of the spring. The weightmay then be removed and a weight of eighty pounds substituted for it.Under these conditions the pointer should be opposite the lineindicating the position B. Should the pointer be too low, the springshould be shortened a little by cutting off a portion of it and thenreset, this operation being repeated until the pointer rests in theproper position. Should the pointer be too high, the outside of thespring may be ground off a little for the same purpose. The sameoperation should be repeated for adjusting the spring to the point A, inwhich case a Weight of one hundred pounds will of, course be substitutedfor the Weight previously used. By pursuing these methods andretempering the spring it is possible to IIO obtain a spring that issuited to all the vary- I ing conditions of a circuit containingtranslating devices, so that perfect regulation can be secured withinthe limits of no load and full load.

The point to be noted is that the regulator is first calibrated to findthe calibration-scale, and then a properly-selected spring is adjustedto meet the conditions of the scale.

The invention claimed is 1. In a system of electrical distribution, anelectric circuit containing a number of translating devices in series, aregulating-reactance device in series with the said translating devicesand consisting of a relativelymovable coil and core whose position withrespect to each other determines the choking elfect of the coil, aspring connected with the movable part of the reactance device andacting in opposition to the magnetic pull thereof, the force of thespring being adjusted throughout its effective range of operation sothat, on a change of resistance in the circuit, it shall bring themoving part of the reactance device to equilibrium at such a point as toproduce the proper choking effect for maintaining the current constant.

2. A regulating reactance device consisting of a relatively-movable coiland core whose position with respect to each other determines thechoking eflect of the coil when the latter is included in an electriccircuit, a spring connected with the movable part of the reactancedevice and acting in opposition to the magnetic pull thereof, the forceof the spring being adjusted throughout its eflective range of operationso as to bring the moving part of the reactance device to equilibrium atdefinite predetermined points representing definite choking efiectscorresponding to anticipated changes of resistance in a circuit.

Signed at New York, in the county of New York and State of New York,this 7th day of May, A. D. 1900.

MALCOLM I'LBAKER.

Witnesses:

GEORGE II. STOCKBRIDGE, TM. II. CAPEL.

